From: Igor Opaniuk igor.opaniuk@toradex.com
Add initial README file which provides all needed information for obtaining a workable image ready for flashing for both eMMC/NAND versions of Colibri iMX7.
Signed-off-by: Igor Opaniuk igor.opaniuk@toradex.com ---
board/toradex/colibri_imx7/README | 107 ++++++++++++++++++++++++++++++ 1 file changed, 107 insertions(+) create mode 100644 board/toradex/colibri_imx7/README
diff --git a/board/toradex/colibri_imx7/README b/board/toradex/colibri_imx7/README new file mode 100644 index 0000000000..729b572574 --- /dev/null +++ b/board/toradex/colibri_imx7/README @@ -0,0 +1,107 @@ +U-Boot for Colibri iMX7 + +Quick Start +=========== + +- Build U-Boot +- NAND IMX image adjustments before flashing +- Flashing manually U-Boot to eMMC +- Flashing manually U-Boot to NAND +- Using update_uboot script + +Build U-Boot +============ + +$ export CROSS_COMPILE=arm-linux-gnueabi- +$ export ARCH=arm +$ make colibri_imx7_emmc_defconfig # For NAND version: colibri_imx7_defconfig +$ make + +After build succeeds, you will obtain final u-boot-dtb.imx +IMX specific image, ready for flashing (but check next section for additional +adjustments for NAND). + +Final IMX program image includes (section 6.6.7 from IMX7DRM [1]): +1. Image vector table (IVT) for BootROM +2. Boot data - indicates the program image location, program image size +in bytes, and the plugin flah. +3. Device configuration data +4. U-Boot image itself (u-boot-dtb.bin) + +NAND IMX image adjustments prior to flashing +========================== + +1. U-Boot for both Colibri iMX7 NAND and eMMC versions +is built with HABv4 support [2] enabled by default, +which requires to generate a proper Command Sequence File (CSF) by +srktool from NXP (not included in the U-Boot tree, check additional +details in [3]) and concatenate it to the final u-boot-dtb.imx. + +In case if you don't want to generate a proper CSF (for any reason), +you still need to pad the IMX image so i has the same size as specified in +in Boot Data section of IMX image. + +To obtain this value, run: +$ od -X -N 0x30 u-boot-dtb.imx +0000000 402000d1 87800000 00000000 877ff42c +0000020 877ff420 877ff400 878a5000 00000000 + ^^^^^^^^ +0000040 877ff000 000a8060 00000000 40b401d2 + ^^^^^^^^ ^^^^^^^^ + +Where: +877ff400 - IVT self address +877ff000 - Program image address +000a8060 - Program image size + +To calculate the padding: +IVT offset = 0x877ff400 - 0x877ff000 = 0x400 +Program image size = 0xa8060 - 0x400 = 0xa7c60 + +and then pad the image: +$ objcopy -I binary -O binary --pad-to 0xa7c60 --gap-fill=0x00 \ +u-boot-dtb.imx u-boot-dtb.imx.zero-padded + +----- + +2. Also, based on requirement from 6.6.7.1([1]), the final image +should have 0x400 offset for initial IVT table. + +For eMMC setup we handle this by flashing it to 0x400, howewer +for NAND setup we adjust the image prior to flashing, adding padding in the +beginning of the image. + +$ dd if=u-boot-dtb.imx.zero-padded of=u-boot-dtb.imx.ready bs=1024 seek=1 + +Flash U-Boot IMX image to eMMC +============================== + +Flash the u-boot-dtb.imx binary to the primary eMMC hardware +boot area partition: + +> load mmc 1:1 $loadaddr u-boot-dtb.imx +> setexpr blkcnt ${filesize} + 0x1ff && setexpr blkcnt ${blkcnt} / 0x200 +> mmc dev 0 1 +> mmc write ${loadaddr} 0x2 ${blkcnt} + +Flash U-boot IMX image to NAND +============================== + +> load mmc 1:1 $loadaddr u-boot-dtb.imx.ready +> nand erase.part u-boot1 +> nand write ${loadaddr} u-boot1 ${filesize} +> nand erase.part u-boot2 +> nand write ${loadaddr} u-boot2 ${filesize} + +Using update_uboot script +========================= + +You can also usb U-boot env update_uboot script, +which wraps all eMMC/NAND specific command invocation: + +> load mmc 1:1 $loadaddr u-boot-dtb.imx +> run update_uboot + +[1] https://www.nxp.com/webapp/Download?colCode=IMX7DRM +[2] https://www.nxp.com/docs/en/application-note/AN4581.pdf +[3] doc/imx/habv4/introduction_habv4.txt